Pulverizing mill



Dec. 16, 1924. 1,519,992

C. H. BREERWOOI? PULVERIZING MILL Filed March '7, 1924 2 Sheets-Sheet 1 65 63 6/ 5 1 a ATTORNEYS c. H. BREERWOOD PULVERIZING MILL Filed March 7, 1924 "H HIH 2 SheetsSheet 2 INV NTOR n K MW Patented Dec. 16,1924.

UNITED STATES PATENT OFFICE,

CHARLES H. BREEZE-WOOD, OF ALLENTOWN, PENNSYLVANIA, ASSIGNOR T FULLER- LEHIGH COMPANY, A CORPORATION OF PENNSYLVANIA.

PULVERIZING MILL.

Application filed March 7, 1924. Serial No. 697,545.

To all whom it may concern:

Be it known that I, CHARLES H. Baum:- wooo, a citizen of the United States, residing at Allentown, in the county of Lehigh,

State of Pennsylvania, have invented certain new and useful Improvements in Pulverizing Mills; and I do hereby declare the following to be a full, clear, and exact tie-- scription of the invention, such as will enable others skilled in the art to which it appertains to make and use the same.

The present invention relates to pulverizing mills such as are illustrated in U. S. Letters Patent No. 849,779; 922,468; 1,039.- 721. and 1,358,837, issued to James W. Fuller, and showing a mill known as the Fuller mill. Pulverizing mills of this type have a pulverizing zone containing a raceway within which operates a series of pulverizing balls actuated by rotating pushers and thepulverized material is raised from the pulverizing zone largely by action of rotating lifting blades which elevate the finely pulverized material into the zone of action of a superjacentseries of fan blades which float it against and through a cylindrical screen which surrounds the upper part of-the pulverizing chamber. In these mills there is provided a vertical shaft ::0 mounted-in appropriate bearings, which carries the yoke providing a support for carrying the movable devices mounted within the mill. These devices include propelling means in the form of pushers which engage and propel the balls, plows which are adjusted to operate 'in the grinding ring or,

race-way, and elevate the ground material therein, a series of superimposed lifting blades which assist in elevating the material from the pulverizing zone, and a multiplicity of fan blades above the lifting blades which serve to float the material through the screen. The yoke consists of a central hub suitably secured to the shaft and at its 'this hub. these arms lying in a horizontal plane.

In the mill illustrated in Patent No. 1.358.837, the yoke is shown to have four of such arms and two of these arms carry pushers which propel the balls and the alternate arms carry plows or scoops for lifting the material from the pulverizing zone into the lower end a plurality of arms radiate from.

zone of action of the superimposed lifting blades. 'Radiatlng from the hub in a plane spaced above'the plane of the arms first mentioned, is another series of arms which carry the lifting blades and each of the second series of arms has a vertical extension to which is secured a ring carrying the fan blades. The construction of this yoke will be seen from aconsideration of Patent No. 1,358,837 to be quite complicated, so that it is expensive to manufacture while in addition the.distribution of the metal in it is not in all respects the most economical.

The present invention is intended to provide a new and improved yoke construction for use in the Fuller mill of the type above referred to, and this invention involves the provision of a yoke which is much stronger than the yoke formerly used, although it is no heavier. The new type of yoke is so designed that all the stresses. occurring in operation are equalized and it may be more readily constructed by casting than was the case with the previous yoke. The new yoke has various other incidental features, such, for instance, as the provision of plow-push ers which are devices performing the com-- bined functions of the separate plows and pushers previously employed, which together with the numerous advantages it affords. will be more apparent from a consideration of the details of its construction.

In one embodiment of the invention the yoke consists of a central hub from which radiate a plurality of armsthe ends of which are connected by a ring. Extending downwardly from and formed as an integral part ofthe ring, is a plurality of arms which are intended to extend into the pulverizing zone. Each of these arms terminates in a square shank on which may be mounted a plowpusher or if the former construction is employed, alternate arms may carry pushers and plows- Formed on the outer side of each arm and extending upwardly and to the rear with reference to the direction of rotation of the yoke, is a lifting blade which serves to create a suction effect useful in elevating the finely ground material into the zone of action of the fan. The latter consists of a plurality of blades which are mounted on brackets extending upwardly from the upper surface ofthe ring although poses of support.

if desired this fan may be formed as a separate unitary structure removable as a whole from the yoke. In the construction in which the fan is an integral part of the yoke the blade-supporting brackets are located be-, tween the depending arms and the ends of the brackets are connected by a ring for pur- The central hub from which the arms radiate is supported and secured in any desired manner on a vertical shaft which may be driven from any convenient source of power in the usual manner. The plowpushers with which the new yoke may be equipped, may take various forms; for instance, that illustrated in my co-pending application Ser. No. 697,544, filed March 7, 1924, or various other forms in one of .which the plow-pusher consists of a body having a socket into which the square shank on the end of the depending arm of the yoke may be inserted and held in place by means of a locking in. The front face of this body is forme so as to engage and propel one of the balls and beneath the ballengaging surface the body of the plowpusher is cut away so as to form a vertical ridge from which extends toward the inner face of the body, a rearwardly inclined face. Also extending rearwardly toward the outer face of the body is another inclined surface which has considerablewidth at the forward end of the plow pusher, but which becomes narrower toward the rear. The outer ,wall

' of the body is cut away so .as to form a channel with'whic-h this surface referred tocommunicates and when the plow-pusher is, in operation the material which would normally be packed *down in the race-wa ,by the passage of the ball is dislodged t erefrom by the action of the inclined surfaces and Dart of it is thrown toward the center of the mill, while part passes-through the channel formed in the outer face of the body and is discharged in the path of travel of the next succeeding ball.

The construction of the mill in which the new form of yoke is used will be clear from a consideration of the accompanying drawings, in which-:-

Fig. 1 is a view in vertical'section of the Fuller mill, taken on the line 1-1 of Fig. 3,

Fig. 2, is a view in elevation of the new type ofyoke with a number of balls shown in their usual relative positions,

Fig. 3 is a top plan view of the yoke illustrated in Fig. 2,

Fig. 4 is a top plan view of one form of plow-pusher,

Fig. 5 is an outer face view of this pusher,

Fig. 6 is affront end view,

Fig. 7 is a view .in side elevation of a modified form of the new yoke.

Fig. 8 is a vertical sectional view of the same,

Fig. 9:-is a top plan view of the fan,

- Fig. 2.

Fig. 10 is a top plan view of the'yoke with the fan removed,

Fig. 11 is a detail view of the yoke-sup-' porting means, and

Fig. 12 is a sectional view on-the line 12 12 of Fig. 11.

Referring to these drawings, the mill is seen to consist of a closed outer casing 13 in the upper end of which is a cylindrical screen 14 of a mesh corresponding to the size of the particles which are to be discharged from the mill. The material to be ground is fed into the upper part of the casing within the screen by a mechanically driven feeder 15 of any appropriate form. Mounted centrally of the casing is a vertical shaft 16 supported in appropriate bearings and carrying a pulley 17 by which the shaft may be driven from any convenient source of power, not illustrated. At about the mid-pointof the mill is placed a grinding ring 18 having a concave inner face.

Mounted on the shaft is a carrier 19 which cooperates with the grinding ring to form a race-way for grinding balls 20. These balls are propelled about the race-way and serve to grind the material in the usual manner.v

The carrier has a hub 21 extending upwardly from its surface and secured to the shaft, as for instance, by means of a key 22, is a yoke 23 which has a hub 24which is recessed to receive-the hub 21. As will be apparent from Fig. 3, a plurality of arms 25 radiate from the hub 24. The yoke illus trated in that figure has four such arms. The ends of these arms are i conneetedby means of a ring 26, and since this yoke is preferablymade by casting, it may be considered to consist of a hub 'onfthe upper end of which is formed a. disc having openings 27 which serve to define the arms 25.

Depending from the ring 26. and formed formed as an integral part thereof, are lifting blades 30. There 'is one of these blades on each arm and it consists of a fin which extends upwardly and rearwardly with reference to the direction of rotation of the yoke. The fin terminates at its lower end at the point where the'squared shank begins so that the end of this blade will lie close to the top of the plow-pusher, as is illustrated in In order to secure the maximum strength in the yoke, the depending arms 28 are dis- .posed opposite the endsv oflthe' horizontal arms so that the points of the ring which receive the greatest stresses by reason of the force which must be applied to move the balls and lift the ground material, are supported by the horizontal arms.

The yoke is also provided with a fan which acts to float the material lifted by the blades against the screen 14. This fan consists of a plurality of blades 31 which extend vertically and are. carried by brackets 32 of a substantially triangular shape, extending upwardly from the upper surface of the ring 26. These brackets are placed between the arms 25 so that each fan blade is to the rear of one of the lifting blades. The upper ends of the brackets are in turn supported by means of a connecting ring 33. The fan brackets may be formed as an integral part of the yoke although it is possible, and in some cases may be preferable,- to make the fan in the form of a separate unit which rests on the hub of the yoke and is driven therewith from thelshaft 16. Since the fan is but little subject to wear this later construction results in considerable economy construction, it might, upon occasion, become necessary to discard the old yoke with the fan attached in cases where the fan is unworn or uninjured.

In Figs. 7 to 11 a modified yoke construction is illustrated in which the fan is formed as a separate unit. In this construction the shaft 16 carries a support 34 suitably secured in place and keyed or otherwise held fast to the shaft. This support consists of a base member 35 which has flattened sides 36 and an integral spindle 37 extending upwardly therefrom. and also having flattened sides. The yoke has a hub 38 having a central recess 39 into which the support 35 may be received, and the hub extends downwardly,

around the support to form a curtain 40.

The recess 39 is shaped so that the flattened sides of the support will engage similar surfaces within the recess so that a driving'connection between the yoke and shaft is provided. As is shown in Fig. 10, the yoke has the usual arms 25, the ends of which are connected by the ring 26, and depending from this ring are the arms 28, terminating in the square shanks 29. On the outside of these arms there are mounted the lifting blades 30 which may be formed as an integral part of the yoke or bolted in place thereon. These lifting blades extend from the upper edge of the square shank-to a considerable distance above the plane of the yoke, as is shown inFig. 7. Devices for propelling the balls and for lifting the material are mounted on the square shanks. In the present case it is intended that these devices shall be plowushers which perform the tending recesses so that the plow-pushers may be mounted on the shanks and held in place thereon by locking pins which extend through the bores in the plow-pusher and the shank. The recesses 45 are provided to permit the introduction of these locking pins. 7

Extending upwardly from the top of the hub is a portion 46 of reduced diameter through which extends the spindle 37 and mounted above the yoke is the fan unit which has a hub 47 provided with a recess 48 in its lower face into which the portion 46 may be received. The hub of the fan has a central opening 49 adapted to receive the spindle 37. The shape of this opening is designed so that a driving connection is made between the spindle and the hub. Extending from the hub of the fan unit are radial arms 50, the ends of which are connected by a ring 51 and disposed about this ring are upward extensions 52 which are triangular in elevation and have a curvature corresponding to that of the ring 51. A fan blade 53 is formed on the outer surface of each extension 52, this blade extending from the upper edge of the extension to the lower edge/of the ring 51. These blades may be secured in place in any desired manner but are preferably cast as an integral part of i the fan member. It will be seen that the planes of the arms of the fan member are spaced a slight distance above the plane of the yoke and the lifting blades 30 extend upwardly below the plane of the .yoke a sufficient distance so that the upper edge of these blades lies in a plane which is substantially that of the lower face of the fan unit. Also the opening 49 formed through the hub of the fan unit is so formed that the fan blades 53 lie in alternation with the lifting blades and there is a fan blade to the rear of each lifting blade so that as the material is ele vated by the latter it will at once come within the influence of the fan and be thrown outwardly against the screen.

It has been explained that each dependlIlU pusher which I find satisfacto for the purpose, although other types o plow-pusher may also be used. The 'plow-pushers which are illustrated in position on the arms in Fig. 2, consist of a. body portion 42'hav1ng a vertical socket 41 in whichthe square shank at the end of the arms is to'be received. In' its front face the body member has a concave surface 54 which serves to engage the ball for propulsion. Above thls front surface thebody is beveled away as at 55 and at its upper outer edge is also beveled as at 56, this bevel extending along the rear face as at 57 and the inner face as at 58. This bevel permits the material to slide from the top of the plow-pusher into the grinding zone. The outer edge of the plow-pusher is formed on an arc and at its forward end as at 59 it lies somewhat in advance of the main,

body of the pusher. The concave surface 54 is defined at its lower edge by a straight line 60 and extending downwardly from this line which may be considered to form a ridge, is another ridge 61. To the left of theridge 61, as shown in Fig. 6, the body is cut away to form an inclined surface 62 and the lower inner edge of the body is beveled as at 63 for a purpose later to be described. To: the right of the ridge 61 the body is formed with another inclined surface 64 and extending outwardly from the lower end of the ridge 61 there is a blade 65 which is of considerable width at its lower forward end, but which becomes narrower toward the rear as it follows the inclination of the surface 64. Owing to the inclination of the surface 64 it will be seen that the concave ball-engaging surface '54 is overhanging at its outer edge, as at 66, and an inclined surface 67 extends rearwardly from the outer edge of the ball-engaging face, finally uniting with the v surface 64 to 'form a broad surface 68. The

blade 65 which becomes narrower to the rear, as has been explained, extends upwardly to the rear edge of the body at 69 and the body,

cut away to provide the inclined surfaces 64 and 67 which extend to the rear'end of the body, is overhanging as at 70 so that a chan-v nel is formed between the upper surface of the blade 65 and the lowersurface of this overhanging portion, both inclined surfaces 64 and 68 communicating with this channel.

This type ofplow pusher will be seen to be admirably adapted for the purpose of propelling a ball and for dislodging the material packed down in the grinding ring by the passage of the ball thereover. The ball is engaged at such a point that it is propelled without the pusher having any tendency to lift or depress the ball. and the lower front ed e of the pusher lies close to the surface of t e race-way, in which the ball moves. The material crushed down by the ball is picked up by the blade 65. The material which is not in the path of this blade, howsufficient to raise the fine particles to the zone of influence of the lifting blades 30. The heavier material, however, discharged from the channel is now deposited in the path of travel of the next succeeding ball so that with this plow-pusher it will be seen that the material cannot pack down in the rin to a suflicient extent to interfere with the 'grinding action. Also it is now possible to use a number of balls corresponding to the num- 1 her of yoke arms and at the same time pro.- vide the plow device which would ordinarily require separate arms. i

By constructing the yoke according to the the blades. Also the different parts of the yoke are so arranged that there are many openings through which the material may pass and this permits rapid circulation which, in turn, renders the mill. more efficient. Also, since the yokes are ordinarily cast it will be seen that the present type of .yoke makes the casting operation much simpler as it is not so complicated as the type of yoke previously used. By making the yoke and fan as separate elements, greater economy is secured, since'the fan unit will last for an indefinite period and need not be discarded should breakage occur in the yoke proper.

- I claim:

'1. In a pulverizing -mill, a pulverizing principles of this invention, it is much freely movable in the race-way, and a single means carried by each of the arms for engaging and propelling the balls and for dislodging the ground material from the surface of the race-way.

3. In a pulverizing mill, a pulverizing zone containing a race-way, a plurality of freely movable grinding balls therein, a rotatably mounted ring above the race-way, depending arms extending from the ring into the pulverizing zone and means carried by the arms for engaging and propelling the balls and for dislodging the ground material from the surface of the race-way.

4. In a pulverizing mill, a pulverizing zone containing a race-way, a plurality of freely movable grinding balls in the raceway, a yoke rotatably mounted above the race-way, a plurality of arms depending from the rim of the yoke and extending into the pulverizing zone, an inclined lifting blade on each arm, and means carried by the arms for engaging and propellingthe balls and for dislodging the ground material from the surface of the race-Way.

5. In a pulverizing mill, a pulverizing zone containing a race-Way, a plurality of freely movable grinding balls in the raceway, a yoke comprising a central hub, a plurality of arms radiating therefrom, and

. a ring connecting the ends ofthe arms, a

plurality of spaced arms depending from the ring, means carried by the arms for engaging and propelling the balls and dislodging the ground material from the surface of the race-way, a lifting bla'de mounted on each arm, and a plurality of fan blades rotatably mounted above the ring.

6. In apulverizing mill, a pulverizing zone, containing a race-way, a plurality of freely movable grinding balls in the raceway, a yoke rotatably mounted above the race-way and comprising a central hub, arms radiating therefrom, and a ring connecting the ends of the arms, a plurality of arms depending from thering and extending into the pulverizing zone, means carried by the depending arms for engaging and propelling the balls and for dislodging the ground material from the surface of the race-way, an upwardly andrearwardly inclined lifting blade secured on the outer face of each depending arm, and a plurality of brackets mounted on the ring, each bracket carrying a fan blade.

7. In a pulverizing mill, a pulverizing zone containing a race-way, a plurality of grinding balls' freely movable in the race way, a yoke rotatably mounted above the race-ways and comprising a central hub, a plurality of arms radiating therefrom, and a ring connecting the ends of the arms, a plurality of arms depending from the-ring,

a plow-pusher on the end of each arm,-

an upwardly and rearwardly inclined lifting blade mounted on each depending arm above the plow-pusher, and a multi-blade fan mounted above the surface of the ring and having a blade located to the rear of each lifting blade.

8. In a pulverizing mill, a pulverizing zone containing a race-Way, a plurality of grinding balls freely movable in the raceway, a yoke rotatably mounted above the race-way and comprising a central hub, a plurality of arms radiating therefrom, a ring connecting the ends of the arms and a plurality of arms depending from the ring, each of the depending arms being located below the junction of a radial arm with the ring, devices on the arms for propelling the balls and for dislodging the ground material from the surface of the race-way, lifting blades on each depending arm and a fan having a plurality of blades located above the radial .arms, each blade of the fan being disposed to the rear of a lifting blade.

9. In a pulverizing mill, a pulverizing zone containing a race-way, a plurality of grinding balls freely movable in the raceway, a yoke rotatably mounted in the mill and comprising a central hub, a plurality of horizontal arms radiating therefrom, a ring. connecting the ends of the arms and a plurality of arms depending from the ring, each depending arm being located below the point of junction of the ring and one of the horizontal arms, a single means carried by each of the depending arms for propelling the balls and for dislodging the ground material in the ring, and a lifting blade mounted on the outer surface of each depending arm.

10. The combination with a pulverizing mill having a plurality of grinding balls movable in a race-way, of a yoke having a plurality of depending arms extending into the race-way, and means on the arms for en" gaging and propelling the balls and for dislodging the material packed down in the race-wa 11. T e combination with a pulverizing mill having a race-way and a plurality of grinding balls operating therein, of a rotatable yoke having a plurality of depend ing arms extending into the race-way, means on the arms for engaging and propelling the balls and for dislodging the material packed down in the race-way, lifting blades along the periphery of the yoke, and a pluralit of fan blades mounted above the lifting la'des.

12. The combination of a pulverizing mill having a grinding ring and grinding balls operating therein, and a yoke rotatably mounted in the mill and comprising a central hub, a ring supported from the hub by means of radiating arms, a plurality of arms depending from the ring, a plowpusher mounted oneach arm, a plurality of supports above the ring, and a fan blade secured to each support.

13. The combination of a pulverizing mill having a grinding ring and grinding balls operating therein, and a yoke rotatably mounted in the mill and comprising a central hub, a ring supported from the hub by means of radiating arms, a plurality of of the supports. 1

' hub, a

. central hub, a

14. A yoke for use in a pulverizing mill bl having agrinding ring and a plurality of balls operative therein, which comprises a hub, a plurality of arms radiatlng therefrom, a ring connecting the ends of the arms,

a plurality of arms depending from the ring into the grinding ring, a lifting blade extending along each depending arm, a plurality of supports spaced about the ring,

and a fan blade carried by each support.

15. A yoke for use in a pulverizing mill having a grinding ring and a plurality of balls operative therein which comprises a plurality of arms radiating therefrom, a ring connecting the ends of the arms, an arm depending from the under surface of the ring at each point of junction of a radiating arm with the ring, a plurality of upwardly and rearwardly inclined lifting blades mounted on the ring, each blade extending along one of the depending arms, and a fan having a plurality of blades mounted above the plane of the ring, each of these blades being disposed to the rear of a lifting blade.

16. A yoke for use in a pulverizing mill having a grinding ring and a plurality of balls operative therein which comprises a central hub, a plurality of arms radiating therefrom, a ring connecting the ends of the arms, a plurality of arms depending from the ring, the hub, the two sets of arms and the ring being of a unitary construction, up-

wardly and rearwardly inclined liftingblades disposed about the ring, and a fan havln a plurality of blades mounted above 1 the p ane of the ring.

17. A yoke for use in a pulverizing mill having a grinding ring and a pluralityof balls .operativetherein which comprises a plurality of arms radiating 7 therefrom, a plurality of arms depending from-the ring,

each'arm being porting a plow-pusher thereon, a lifting blade extending along each depending arm,

and a fan mounted on the hub and comprising a hub having a plurality of radial arms connected by a rim, a plurality of vertical 7 grinding balls freely movable a ring connecting the ends of the arms,

supplied with means for supyoke and comprising a central hub, a plurality. of arms radiating therefrom, the ends of which are connected by a ring and a plurality of vertical extensions from the fan ring, each of these extensions carrying a 19. In a pulverizing mill, the combination of a grinding ring, grinding balls operating in the ring, a driven shaft extending through the ring, a yoke support mounted on the shaft, and providedwith a spindle extend-' ing along the shaft, a'yoke carried on the support'and having a hub formed with a socket into which the support is received, a i

plurality of-arms extendlng from the hub, a rin connecting the ends of these arms, and

a" p urality of arms depending from the ring and carryin plow-pushers thereon, for propelling the alls, a fan resting on the hub and ofperatively connected with the spindle, thlsan having a central hub fitting the spindle, a plurality of arms extending there from, the ends of the arms being connected by a ring, vertical extensions f om the ring, a blade secured to each extensid n, and a' plurality of lifting blades secured to the outer edge of the yoke ring, and extending between the fan blades and the plow-pushers.

20. A yoke for use in a ulverizing mill having a grinding ring and a plurality of therein, which comprises a central hub, a plurality ofsubstantially horizontal arms radiating therefrom, a ring connecting the endsQf the arms, and a plurality of arms 'depending from the ring and 'equidistantly spaced about the ring, the extremities of these arms being shaped to receive devices for propelling the balls and for dislodging the material passed over by the balls. Y i

21. A yoke for use. .in a ulverizin mill having a grinding ring an a plurality of grindlng balls freely movable therein, which comprises a central hub,.a plurality of substantially horizontal arms radiating therefrom, a ring connecting the ends of the arms,'. and an arm-depending from the ring below. each -point of junction of the ring with a horizontal arm. 22 A yoke for use in a pulverizing mill havin a grinding ring and a plurality.of grindlng balls freely movable therein, which comprises a central hub, a plurality of hori- J zontal arms radiating therefrom, a ring connecting the ends of the arms, an arm depending from the ring at each point of junction of the ring with a horizontal arm, and a lifting blade extending along each depending arm.

23. The combination of a yoke having a central hub, a ring mounted thereon, and arms depending from the ring, of a plowpusher mounted on each arm, this plowpusher having a body provided with a ballengaging face, a vertical ridge formed in the body, extending downwardly from the lower edge of this face, an upwardly and rearwardly inclined blade extending outwardly from the lower edge of the ridge and a channel formed in the outer face of the body with which the inclined blade communicates.

24. The combination of a yoke having a central hub, a ring mounted thereon and. arms depending from the ring, of a plowpusher mounted on each arm, this plowpusher having a body portion socketed to receive a portion of the depending arm, a ball engaging face formed on the body, a vertical ridge extending downwardly from the lower edge of the said face, and a pair of inclined surfaces extending rearwardly from the ridge, the outer of these surfaces communicating with a channel formed in the outer wall of the body and extending to the rear thereof.

25. The combination of a yoke having a central hub, a ring mounted thereon and arms depending from the ring, of a plowpusher mounted on each arm, this plow pusher comprising a body portion having a ball-engaging face, a vertical ridge extending downwardly from the lower edge of this face, inclined surfaces extending rearwardly from the ridge, a channel formed in the outer face of the body and extending to the rear edge thereof, this channel communicating with one of the inclined surfaces which terminates at the ridge, and a blade extending outwardly from the lower edge of the ridge-and having an u wardly and rearwardly inclined face WhlCll merges into the lower wall of the channel.

In testimony whereof I aflix my signature.

CHARLES H. BREERWOOD. 

